Dual-comparator current-mode rectifier

A method comprising:

• receiving AC power, by a receive coil, through electromagnetic waves from a wireless power transmitter;
• generating, by the receive coil, an AC current in response to receiving the AC power;
• rectifying the AC current by using a bridge circuit comprising a first comparator circuit, a second comparator circuit, a first field-effect transistor (FET) switch and a second FET switch;
• and
• setting, by the first comparator circuit and the second comparator circuit, a dynamic turn-on threshold for the second FET switch and the first FET switch, respectively,
• wherein:
• a first branch and a second branch of four branches of the bridge circuit are coupled to a first node and a second node of the receive coil, and include the first comparator circuit and the second comparator circuit, respectively,
• the first FET switch is a first sense FET switch of a first differential pair of FET switches including a first power FET switch having a shared gate with the first sense FET switch to allow the first sense FET switch to track an operating mode of the first power FET switch, and
• the method further comprises tracking an operating mode of the first power FET switch by the first sense FET switch.

An apparatus for wirelessly receiving power, the apparatus comprising:

• a receive coil coupled to a load through an H-bridge circuit and configured to generate a AC current in response to receiving AC power through electromagnetic waves from a wireless power transmitter, the H-bridge circuit comprising:
• a first branch coupled to a first node of the receive coil, the first branch including a first circuit including a first comparator and a first switch circuit;
• a second branch coupled to a second node of the receive coil, the second branch including a second circuit including a second comparator and a second switch circuit;
• and
• a third branch and a fourth branch including a first FET switch and a second FET switch coupled to the first and second nodes of the receive coil, respectively,
• wherein the first circuit and the second circuit are configured to set a dynamic turn-on threshold for the first switch circuit and the second switch circuit, respectively, wherein the first switch circuit includes a first differential pair of field-effect transistor (FET) switches including a first sense FET switch and a first power FET switch having a shared gate configured to allow the first sense FET switch to track an operating mode of the first power FET switch, and wherein the second switch circuit includes a second differential pair of FET switches including a second sense FET switch and a second power FET switch.